package io.renren.common.utils;

import cn.hutool.core.util.StrUtil;
import jakarta.servlet.http.HttpServletRequest;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.StringUtils;

import java.net.InetAddress;


/**
 * IP地址
 *
 * @author Mark sunlightcs@gmail.com
 */
public class IpUtils {
    private static final Logger logger = LoggerFactory.getLogger(IpUtils.class);
    private static final String LOCAL_IP = "127.0.0.1";
    private static final String LOCAL_IP1 = "0:0:0:0:0:0:0:1";

    /**
     * 获取IP地址
     * <p>
     * 使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
     * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
     */
    public static String getIpAddr(HttpServletRequest request) {
        String unknown = "unknown";
        String ip = null;
        try {
            ip = request.getHeader("x-forwarded-for");
            if (StrUtil.isEmpty(ip) || unknown.equalsIgnoreCase(ip)) {
                ip = request.getHeader("Proxy-Client-IP");
            }
            if (StrUtil.isEmpty(ip) || unknown.equalsIgnoreCase(ip)) {
                ip = request.getHeader("WL-Proxy-Client-IP");
            }
            if (StrUtil.isEmpty(ip) || unknown.equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_CLIENT_IP");
            }
            if (StrUtil.isEmpty(ip) || unknown.equalsIgnoreCase(ip)) {
                ip = request.getHeader("HTTP_X_FORWARDED_FOR");
            }
            if (StrUtil.isEmpty(ip) || unknown.equalsIgnoreCase(ip)) {
                ip = request.getRemoteAddr();
                if (ip.equals(LOCAL_IP) || ip.equals(LOCAL_IP1)) {
                    // 根据网卡取本机配置的IP
                    InetAddress inet = InetAddress.getLocalHost();
                    if (null != inet) {
                        ip = inet.getHostAddress();
                    }
                }
            }
            // 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
            if (StringUtils.hasText(ip) && ip.length() > 15) {
                // "***.***.***.***".length()
                if (ip.indexOf(",") > 0) {
                    ip = ip.substring(0, ip.indexOf(","));
                }
            }
        } catch (Exception e) {
            logger.error("IPUtils ERROR ", e);
        }

        return ip;
    }

}
